fiestaturbo.com

[jayrs]

hmm ill have a look mate too.

[heeman10]

Update

My air filter-to-turbo pipe arrived back in my hands today. I sent it back to Lee at Fusion Fabrication for some modifications to allow me to use my recirculating dump valve as it is intended. Most dump valves we see are atmospheric, which means that when you lift off the throttle, the pressurised charge air is released into your engine bay with a loud hiss. The recirculating valve diverts the dumped air back round to the airbox (if you have one), or back round to part of the inlet system which comes before the turbo compressor.

To go over some basics, dump valves are designed to release stagnant, pressurised air. Once the turbo's been creating positive pressure, and the throttle is closed, the pressure in the system increases drastically and rapidly, which causes the turbo to stall (stop spinning). As a result, when you come to put your foot down again, it takes some time for the turbo to accelerate again, and the time you have to wait is called "lag", which particularly affects bigger turbo's.

Here is a picture of my dump valve in place:



The blue vacuum hose at the top connects to the throttle body. When the throttle is closed (i.e. I take my foot off the throttle) the engine creates a vacuum in this hose at the top of the valve. At the same time, the pressure build-up in the boost hose creates positive pressure pushing up from the bottom of the valve. These two pressure differences are what open the valve, and when it opens, the pressurised air is diverted out sideways through the port you can see at right angles to the body of the dump valve. (With the throttle open, there is positive pressure in the vacuum hose which is what stops the valve opening when on boost)

Without the recirculating hose in position, I will get the same "pschh" sound all atmospheric dump valves give. Since I don't want that sound, I will be connecting a hose from this right angle port down to my air filter pipe, which you can also see in the picture above (big shiny pipe that goes between the air filter and compressor housing on the turbo). This way, the released air will be sent straight back round to the turbo, which reduces the noise created from the dump valve.

Here is the modified pipe I got back today, showing the 25mm stub that directs air into the turbo:





I made sure my instructions were clear, and that the stub was to be angled so the recirculated air was sent TOWARDS the turbo. The good thing about recirculating valves is that the dumped air isn't wasted as with atmospheric valves. If the stub had been angled AWAY from the turbo, I would be risking starving the turbo of air by creating a large volume of air moving away from the compressor, which would make lag even worse.

I've been thinking for a while about how I could tune the amount of air the dump valve releases (or rather, at what pressure it's activated) and have only come up with two methods.

1. Influencing the flow capacity of the vacuum hose
2. Influencing the flow capacity of the recirculating hose.

I'd like to be able to play with it from the cabin, allowing me to choose between full dumping, chatter only, and a mix of the two. So far my most successful idea has been to locate a ball valve in the recirculting hose between the dump valve and air filter pipe. I could couple this up to a push/pull cable, allowing me to fully open and fully close it from the driver's seat. That way, I could block off the recirculating hose, which would give nothing but chatter (as it is now), or allow all the air to be dumped round to the turbo, giving silent operation.

More importantly, I suspect that if ALL the pressurised air is dumped, then the work needed to re-fill the boost lines could equate to the work needed to overcome compressor stall. I feel there could be a happy medium where JUST enough pressured air is released to minimise compressor stall while leaving pressurised air ready to be injected into the engine when back on the throttle. Watch this space anyway! Just trying to get the recirculating hose which will be funny dimensions, hopefully SFS are helping me out there

[heeman10]

Update 2

Hose will be made up by SFS and with me in about two weeks, in nice shiny blue of course! So next time I'm home I can fit it all (takes about 10 minutes) and see how it sounds and how it affects lag time. Will update again before tooo long

[mike_wall15]

Nice detailed update James!
You not back at uni yet? Work by lee looks good, it'll be interesting to see how the recirc aids your drive

Mike

[heeman10]

I've been back two weeks today Mr Wall! That doesn't stop my brain ticking and phone twitching! The car's SORN as well, but with the Autosport International show coming up on Thursday I suspect I'll be trooping home with a few toys to fit to it next time I can get home!

[mike_wall15]

When did you take those pics then of your car? Something over Xmas that you've only just updated?
Shame it's on SORN, no popping home for a quick drive

[mike_wall15]

Oh, and shame I have exams on thurs and fri, could have seen you at AutoSport! Hope you get some good bits!

[heeman10]

The pic of the car above is from about May 10th IIRC! Possibly even earlier! I've only done 12 miles with the dump valve in, it hasn't been near the car for about 8 months! I had the pipe sent to me here at uni, which is how I took those two pics! Shame you can't make it to the show, Thursday's the first trade day, SO much better than the public days!

[FezzR]

surely a dreaded bleed valve will work as your controller, instead of bleeding the actuator hose you'll bleed the dump valve hose

[heeman10]

Bleed which dump valve hose, and where to? What would I gain by bleeding? If I bleed the recirculator hose all I'm doing is losing dumped air, which is worse than sending it back to the compressor wheel.

[Pez]

Try and stay away from nasty push/pull cables. Damn things are nothing more than a total pain in the arse. And ancient technology. Im sure you can come up with something a little more sohphisticated than that if you try hard

[heeman10]

A potentiometer/servo combo attached to the ball valve would be nice, but I know what the under bonnet temperatures are like on my car, and don't see a little motor lasting too long matey! There's nothing wrong with a good push/pull cable, e.g. throttle cable

[Pez]

There is when they seize up Have a look at some motorbike sites and stuff, see what they are using for clutch cables and the like, and maybe try and in line oiler to keep it fresh

[heeman10]

I'd expect a good quality bicycle brake cable/outer to work well. There are cable outers out there with soft plastic liners inside the metal outer, and the cable passes through this plastic liner. They're smooth as anything and don't gunk up. My throttle cable's never a problem, and the ball valve wouldn't need a great deal of force to move it. If you have a better idea let me know, but this one's simple and should do the job without a problem!

[Excursion]

Nobody Does It Like Recirculating. Happiness is Recirculating-Shaped. For That Deep Down Body Recirculating.

[heeman10]

I wonder what site inspired THAT little reply fest!

[FezzR]

bleed the vacuum hose going to the recirc- dump valve same way that it would normally be used on the vacuum hose to an actuator, you would probably need change the spring in the dump valve though i would have thought

[heeman10]

Just been having that discussion with Scort, and I believe I'd give myself idle problems playing with the vacuum hose in that way rather than modulating the exhaust air (recirculated air) flow.

[chris-fiesta]

nice, detail up date fella, guess we just gotta wait for the vids now!!

chris

[FezzR]

i dont know much about bleed valves and i dont know how they vary, if it bypasses the vacuum from the hose to atmosphere you will get idle problems. if it just acts as a restriction i cant see it causing a problem

[ianFRST]

jimbob - could i pester you for spme pictures of your radiator please?

ive just realised my rad is an exact copy of the original frst radiator and the water pipes go into the left hand end of the radiator, and not the front / back face as i thought

[heeman10]

chris-fiesta -Yep, I'm going to try to get some webspace of some sort to put some of my videos up, so will upload any new ones to there. I fancy bringing someone back home with me at some point to get some better shots from a camera car and general external videos of the car on the move

FezzR - Yeah it'd be a 3-way valve, IN being the vacuum feed from TB, OUT1 being the exit to the vacuum hose downstream of the valve, OUT2 being the bleed-off port. If you think about it though, "bleeding" a vacuum isn't the same as bleeding positive pressure and I just don't think it'd work

ianFRST - Pics taken from page 8 of this thread:

Where it fouled the intercooler:



Marked up for modifying:





I do have more pictures in my photobucket account and on my computer if they're of no use, just let me know what it is you want to see. It was modified further, with the small (12mm I think) stub brought round to point rearwards as well, then the whole radiator turned upside down and mounted with the single port on the passenger side of the car, the two ports being on the driver's side.

edit: Some more pics in this thread from when it was punctured by the turbo that night the gearbox mount snapped. These pics show the repairs made by Pro Alloy: http://www.fiestaturbo.com/phpBB/viewto ... ight=wayne

[garyhurn77]

looking good fella! dump valve looks ace!

after your good words about lee he is now modifying my intercooler for my ka!

[Swanick]

just been through all this again, its certainly inspiring

[heeman10]

Gary - Good, you can do no better!

Swanick - Accepted your MSN tonight, so will catch up with you at some point

[heeman10]

Update

1. Burst radiator

I returned home for the weekend last week (4th Feb), planning to drive the Fiesta back down to uni because I've missed it so much. Warming it up to drive back, it suddenly started steaming through the bonnet vents. I found this to be due to the damage caused to the radiator by what can only have been the cold. There was about a 60-75% antifreeze mixture in it, but prolonged temperatures of -5 to -14 back home clearly took their toll. As the radiator was custom made in aluminium, and modified to fit my car and the custom made hoses/water pipes, I won't be buying another. It will be with Pro Alloy this coming Monday for testing and either repair or re-core.

2. Dump valve fitment

Whilst home, I fitted the dump valve. The recirculating hose hadn't arrived, so I just had it dumping to atmosphere. A couple of short blasts up the drive (with steam pouring over the windscreen ) gave a pleasant surprise - it's already a pretty quiet valve! I get about four or five chips of chatter then a quiet release of the boost pressure, which continues for about 3 seconds after I've come to a standstill. Proof, if ever there was any, that the T3 builds up some serious momentum!

3. Recirculating hose arrived

The hose, made for me by SFS, arrived earlier this week. Here is a picture to show where it'll fit. Remember, this is the hose that'll be taking the dumped waste boost pressure from the dump valve back round to the turbo inlet, which saves total wastage of the air, and should make the valve almost silent in operation:



4. The biggest development - MORE BOOST

Yes, that's right..I need more. I have done for some time, after about 1,000 miles (just under two weeks) I could safely say I was used to my four-times-standard power. The car is still enjoyable, but I feel more would be a good thing. After careful thought, I think it's a safe thing to do. It currently peaks at 15psi and holds 12psi, but my turbo, intercooler, injectors and driver are all good for the extra 3psi.

Those who have read this thread will know my engine's "weak spot" is the pistons - standard cast pistons. They won't enjoy prolonged high engine speeds under load, but the actual production of power isn't a major issue for them. The heat induced by long periods of full throttle under load is what would cause problems, but I'm constantly mindful of that and drive to suit. The extra 3psi will make a considerable difference to the car, I'm guessing around an extra 20-35bhp, which is pretty much another 15%. It's a very exciting prospect, and it'd be very welcome at Bruntingthorpe going for quarter mile times! The engine's still only on 12,000 miles and gets treated well, so this shouldn't be a case of "Ohhhhhhh I turned the boost up too muuuuuuuuch ", it should be within the engine's limits I'll get in touch with MSD and go from there. Updates and videos to come

[MAD_Adamski]

suggest you go buy a better alloy rad next time mines fine on the cossie

[heeman10]

Do you have any idea about water and freezing? Hint: The radiator makes no difference!

[mike_wall15]

Well you should easily be able to knock some 0-60 times off now you put the boost up!
So if you wind the boost up, does that mean it needs to be mapped again?

I like what you're doing with the re-circ dump. Is there an easy way to measure if it makes any difference compared to if it was to atmosphere?

[heeman10]

Yeah the 0-60 could well drop a touch more, still need to sort the clutch pedal though. The quarter will be the time that'll really benefit from 250bhp rather than 220-230 or so.

It won't need mapping again as such, provided it doesn't start detonating with the extra boost. It should just need a run through to check the fuelling, but I'll speak to MSD next week some time to hear their thoughts on it.

In terms of spool-up times between the atmostpheric and recirculating arrangements, all I can really do is see it feels any different. I don't expect a huge change, the main gain will be the quieter operation

[mike_wall15]

Yeah the 0-60 could well drop a touch more, still need to sort the clutch pedal though. The quarter will be the time that'll really benefit from 250bhp rather than 220-230 or so.

It won't need mapping again as such, provided it doesn't start detonating with the extra boost. It should just need a run through to check the fuelling, but I'll speak to MSD next week some time to hear their thoughts on it.

In terms of spool-up times between the atmostpheric and recirculating arrangements, all I can really do is see it feels any different. I don't expect a huge change, the main gain will be the quieter operation

Quieter operation, what's wrong with a big LOUD DV? You need something to scare those sheep!

Can't wait for the pedal post, it'll either be lots of cursing or you'll be very smug in having done it without problems!

Get it on the rollers

[Excursion]

MO' BOOST! THAT'S WHAT WE WANT

[heeman10]

Mike - I dunno, I'd like a few dump valves really, I like all the sounds turbo cars make, including sequential BOV's and loud dump valves, chatter etc...the valve I have at the minute sounds cool as hell, but at £110 a pop it's not really something you (or I, anyway) want to shell out for every week to "try something new"! It does still chatter for maybe a second, then dumps with a gentle continuous whoosh

The pedal thing won't be fun, but shouldn't be the end of the world. I'm now hearing the later pedal has a kink in it that pushes it right over next to the centre console That sounds crap, so I might even be leaving it as it is for Brunters, as much of a shame as that would be. As for the rollers...I'll undoubtedly do it at some point, I'm just in no particular hurry. It doesn't make it faster, so isn't at the top of any lists really!

Excursionay - Mo boost mo problems!

[mike_wall15]

Quite agree, they're expensive things, I don't know how you afford it! With my little income a month I still struggle!
Can't wait to see it at Brunters. The early weeks of April are part of my 3 weeks off so I'll be driving down and walking through the gates at the very least!
Look after it amigo so brunters goes without a hitch!

[heeman10]

I have no plans to damage it Mike, would like to give you your drive in it still